Field of the Disclosure
The present inventions relates to centrifugal clutch apparatuses for transmitting and cutting off the driving power of a driving device (e.g., engine of a motorcycle) to a driven device (e.g., a transmission of a motorcycle). Some of the embodiments disclosed herein are configured to connect and/or disconnect a driving-side rotational member to an inner circumferential surface of a driven-side rotational member via friction members.
Description of the Related Art
Clutch apparatuses are usually arranged in a power transmission train for transmitting the driving power of an engine of vehicle (e.g., engines of motorcycles scooters) to a driving wheel. Some vehicles use a centrifugal clutch apparatus, which operates using centrifugal force, as a main clutch apparatus. Such centrifugal clutches typically comprise, as disclosed in Japanese Laid-open Patent Publication No. 36806/2004, a driving plate connected to a crank shaft of an engine, clutch devices (clutch shoes) swingably mounted on the driving plate, and a housing having an inner circumferential surface against which the clutch shoes can abut via friction members (facings) when the clutch shoes are swung by the centrifugal force.
The driving power of an engine can thus be transmitted to an output shaft when the friction members abut against the inner circumferential surface of the housing due to swing motions of the clutch devices (clutch shoes) when the rotation of the driving plate exceeds a predetermined speed. Each surface of the clutch devices (clutch shoes) opposing the inner circumferential surface of the housing is formed having a circular arc configuration with a friction member secured on the circular arc surface.
In some centrifugal clutch apparatuses, a noise referred to as “clutch squeal” is sometimes caused during a process in which the clutch devices contact the inner circumferential surface of the housing and slide thereon via the friction members (i.e., a period of time between when the friction members contact the inner circumferential surface of the housing and when the housing increases its rotational speed match the rotational speed of the driving plate). To suppress generation of the “clutch squeal”, Japanese Laid-open Patent Publication No. 236140/1997 suggests a centrifugal clutch apparatus in which a vibration isolating ring is crimped around the outer circumferential surface of a housing.